Friday, June 12, 2009

Skiing that San Juan dirt-snow

Well all know about it: those crazy, hazy dust storms that swept across the Four Corners this spring. Seems that southern Utah and northern Arizona was scoured down with this Spring's winds, carried across the Colorado Plateau, and deposited on the spring snowpack sitting on the flanks of the Rockies -- and particularly the San Juan Mountains.

It also seems that these dark layers dusted over the snowpack -- we Westerners' alpine-stored water supply for the dry Summer months ahead -- also speeded up the snowmelt. By darkening the snowpack and lowering its albedo, the snowpack absorbed more solar radiation and so delivered its peak runoff weeks early.

And it seems the people who prognosticate on such things are predicting more of the same dirt-to-dust-to-snowmelt in the years ahead.

The New York Times ran a good article on the phenomenon a few weeks ago. The article, published May 14, says:

Snowpacks from the San Juan Mountains to the Front Range have either completely melted or will be gone within the next two weeks, said Tom Painter, director of the Snow Optics Laboratory at the University of Utah and a leading expert on snowmelt.

The rapid melting is linked to a spate of intense dust storms that kick up dirt and sand that in turn are deposited on snow-topped mountains. The dust darkens the snow, allowing the surface to absorb more heat from the sun. This warms the snow -- and the air above it -- significantly, studies show.

The problem has been particularly acute in the semiarid Colorado Plateau region encompassing parts of Utah, Colorado, New Mexico and Arizona. An unprecedented 12 large dust storms have occurred so far this year in the region, and at least two more are projected in the coming months, officials say.



The article also says there has already been twice as much dust generated this year than in the past six years.

That, to me -- even though I, too, recognized something weird going -- seems like a hard thing to quantify.


But, I must say, after a late-spring ski venture up into the San Juan high country recently, I am a convert to the idea that, this year at least, something truly peculiar hath descended upon our mountain domain.


As a side note, this trip was also my teen kids', and one of their friend's, first backcountry ski venture. (We're already getting them fired up for next year.) We headed up early one morning to Cinnamon Pass, east of Silverton. It was a great spot for their inaugural snowfield-skiing experience -- a quick 15-minute climb rewarded by a fast, fun, steep descent down. We got in two runs before the weird-as-the-dust-storms stormy weather moved in, packing its winds, cold, sleet, and lightning.


But two runs was enough to full hook these ski-bum kids.


And it was also enough to see first-hand the effects the Spring's dust storms had wreaked on the high-country snow. Looking out over the ragged ranges of peaks, both nearby and far away, you could clearly see -- startlingly see -- the line of red dust painting the snow-covered slopes, fading to a thinner pink as you got higher. It's a truly bizarre and dumbfounding sight.


And the effect was also clear close-at-hand: although our skiing was fast and fun, it was also across gritty, rust-colored corn snow.


If this is what's to come, then maybe it's time to turn those rock skis into dirt skis.


See more pics of both the ski and the dirty San Juans below.



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